The following abbreviations that may be found in the specification and/or the drawing figures are defined as follows:
CBScell broadcast serviceCDMAcode division multiple accesseNodeBevolved Node BHSShome subscription serverIWFinterworking functionLTElong term evolutionM2Mmachine-to-machineMTCmachine-type communicationPLMNpublic land mobile networkRArandom accessUEuser equipment
Machine to machine (M2M) communication is the networking of intelligent, communications-enabled remote assets. It allows important information to be exchanged automatically without human intervention, and covers a broad range of technologies and applications which connect the physical world—whether machines or monitored physical conditions—to a back-end information technology infrastructure. M2M communications can be used for a variety of purposes, such as immediate feedback or control on a remote asset, feature popularity, and specifics of errors and breakdowns, to name a few.
M2M communications are made possible by the use of elements such as intelligent sensors, actuators or microprocessors that are embedded in the remote asset. Sensors and actuators may be connected to a wireless modem, possibly different from those in conventional mobile phones. Such a wireless modem is able to wirelessly receive data from a central server, and transmit data to the central server where it can be analyzed and acted upon. Wireless communications technologies used to enable this connectivity include GSM, GPRS, CDMA, 3G, LTE, Wi-Fi and WiMAX, and M2M communications can be conducted over a relatively short range or a distance of many miles. Since M2M communications vary widely in both the types of data reported and the radio access technologies used, the traffic models are quite diverse and no single networking model is efficient for all of them. For example, if M2M is applied to monitor natural disasters, a huge number of M2M devices may initiate services simultaneously, with each reporting a small amount of data to the application layer when triggered by an appropriate event. This is classified as an infrequent small data transmission. In conventional cellular systems a mobile terminal typically goes through a control signaling procedure to establish a data connection with the network before it can send user data. This is inefficient for infrequent small data transmissions since the conventional signaling overhead in setting up a data channel for the user terminal is high relative to the small volume of user data being reported by an MTC UE. Because MTC UEs transmit relatively infrequently, the network load imposed by their normal data transmission is very low. For this reason, large numbers of MTC UEs may be present in a geographic area served by a network. The expectation is that very few of these devices will transmit at any one time, so the presence of even very large numbers of them will not overload the network.
However, data signaling is not the only source of load imposed by MTC or other devices. Control signaling also imposes a load on a network, and must be minimized in order to achieve network efficiency and avoid overload.